Signal device



March 26, 1940. M LORD tr 2,194,507

SIGNAL DEVICE Filed April 28, 1939 4 Sheets-Sheet 1 5y gz/ezwjl Vdrren 774a; ATTORNEY.

March 26, 1940. D AL 2,194,507

SIGNAL DEVICE Filed April 28, 1939 4 Sheets-Sheet 2 ATTORNEY.

March 26, 1940. M, LORD AL 2,194,507

SIGNAL DEVICE Filed April 28, 1939 4 Sheets-Sheet 35 INVENTORS March 26, 1940. R M 2,194,507

SIGNAL DEVICE Filed April 28, 1939 4 Sheets-Sheet 4 INYENTORS Mb 62?) .lzifpluren. 2

Zia ATTORNEY.

Patented Mar. 26, 1940 UNITED STATES PATENT OFFICE SIGNAL DEVICE Application April 28, 1939, Serial No. 270,590

7 Claims.

This invention relates to a signal device, of the particular type involving a chime unit such as a bar or plate combined with electrically operated striker-actuating means such as a solenoid, and it has for its object to aflord an eificient and practical construction that will give a two-tone signal and is adapted to telephone sets, to take the place of the conventional vibrating ringing bell.

A further object of the invention is to provide a construction in which the parts are compactly arranged so as to occupy a minimum space, with a single electrically operated striker-actuating means controlling two chime units or bars, and all located and enclosed within a housing in such a way as to effect a two-tone signal of suitable volume.

An additional purpose of the invention is to provide an arrangement embodying two resonance chambers and chime units arranged within an enclosing housing, the resonance chambers and housing being constructed invsucha manner as to emit the tones from the resonance chambers in suitable volume when the chime units are struck.

Another object of the invention is to afford a construction and arrangement of two resonance chambers and chime units designed to emit full, rich tones for use in telephone signaling, and to be covered by an enclosing housing that protects and conceals the necessary electrical units and connections.

A further purpose of the invention is to provide an arrangement of two resonance chambers'and chime units actuated by a single electrically operated striker-actuating means which moves a plunger upwardly for engaging one chime unit or bar while the plunger is operated in the opposite direction by gravity to strike the other chime unit or bar.

An additional object of the invention is to afiord a simple and practical form of resonance chamber, designed to be used in conjunction with a chime unit and surrounding housing, and to emit a deep full tone of required volume.

Still another object of the invention is to provide an emcient type of cover or housing for en-.

closing two resonance chambers and chime units so as to conceal the parts and present an ornate- To these and other ends, the invention consists in the construction and arrangement of parts that will appear clearly from the following description when read in conjunction with the accompanying drawings, the novel features being pointed out in the claims at the end of the specification.

In the drawings:

Fig. 1 is an enlarged front view of an illustrative embodiment of the invention, the housing appearing in section;

Fig. 2 is an end elevation with the housing removed;

Fig. 3 is a vertical sectional view on the line 3-3 of Fig. 2;

Fig. 4 is a sectional view on line 4-4 of Fig. 1;

Fig. 5 is a front elevation of the housing;

Fig. 6 is an end elevation of the same, and

Fig. 7 is a top plan view.

Referring more particularly to the drawings in which like reference numerals refer to the same parts throughout the several views, 5 designates the base, see Fig. 1, on which the several parts are mounted, while 2 and 3 designate horizontally arranged upper and lower resonance chambers respectively. These may be of rectangular crosssection and provided at their ends with flanges s that are adjustably attached to the base i by means of screws or fastening elements 5 extending through elongated slots 6 in the flanges l and attached to the base. This arrangement enables adjusting each or both of the resonance chambers to vary the volume or tonalefiect.

l designates a solenoid located between the upper and lower resonance chambers and preferably closer to the upper'resonance chamber as shown. It will be understood that the solenoid l is energized to operate a striker when the ringing current is imposed on the line, as usual in this class of construction, the particular construction of solenoid and arrangement of circuit forming no part of the present invention. 8 designates a tube extending through the solenoid l, the lower end of said'tube extending through an opening 9 in the upper wall of the lower resonance chamber 3 while the upper end of the tube 8 extends to a point just below the opening III in the lower wall of the upper resonance chamber 2, through which opening thestriker operates.

Within the tube 8 is arranged a plunger H which carries a striker element I2 at its upper end that is movable through the opening ID in.

the upper resonance chamber tofengage the upper chime bar, and a striker element l3 at its.

ancccov ing, the striker element [13 moves through a coil spring to that is supported one flange it at the lower end of the tube ii, said spring to normally engaging the lower end of the plunger M and holding the striker element out of engagement with the chime bar after the latter has been struclr.

it and ill designate the chime units or bars which may be either outside or within the upper and lower resonance chambers, and which are here shown located inside the chambers in parallelism to their lower and upper walls respectively and spaced therefrom, the chime bars being supported by suitable bolts or other devices it, as usual in this class of construction.

When the solenoid l is energized, the plunger ii is drawn upwardly, causing the upper strilrer l2 to engage the upper chime bar it, and as soon as the solenoid is deenergized, the plunger ll :lalls by gravity, causing the lower striker it to contact the lower chime bar ll. The lainetic energy or momentum of the plunger M is sumcient to overcome the action of the spring 141 which is compressed slightly to permit striking the chime bar, after which the spring immediately resumes its normal state and moves the'plunger upwardly sumciently to disengage the striker from the chime bar.

Each resonance chamber is open at one end, their open ends being oppositely arranged as shown, the upper resonance chamber 2 having an open end it at its left hand end, referring to Fig. l, and the lower resonance chamber having an open end 20] at its right hand end. Elie other ends of the respective resonance chambers are preferably closed, the tones being emitted mainly irom the open ends thereof.

The housing, which may be attached to the base in any suitable manner, includes a top wall 2% having suitable openings 22 therein, and end walls 23 and 24. The end wall 23 has a series of slots or openings 25 at its upper portion opposite to the opening IS in the end of the upper resonance chamber 2, while the other end wall 24 of the housinghas openings at at its lower portion opposite to the open end it in the lower resonance chamber 3.

Each resonance chamber is tuned, the size of each opening Ill being determined in relation to the open end of the resonance chamber, in order that the resonant frequency of vibration of the column of air inside the chamber will be the same as that of the chime bar.

It has been ascertained that the resonance chamber can be properly tuned with the opening in the side wall in addition to having one end of the chamber open, and by so doing, most of the sound is emitted through the open end and is thence directed through the openings in the opposite wall of the enclosing housing. The onclosing housing is necessary in a telephone signal construction of this character in order to protest the mechanism from dust and dirt, and also to afiord a suitable ornamental appearance, and when such housing surrounds the resonance chamber, it is essential that a maximum volume of tone of suitable quality be emitted through the enclosing housing.

It has been ascertainedthat much more efloctive results are had by providing the resonance chamber with an open end and locating openings in thewall or the enclosing housing opposite to such open end of the resonance chamber... The desired results cannot be attained if the enclosing housing has openings only on its front. wall and both ends of each resonancechber are closed.

With this arrangement, most of the sound is emitted irom the open end or the resonance chamber, and therefore a maximum volume ct tone passesto the outside through the openings in the housing opposite the open end of the resonance chamber, thus producing an arrangement that is acoustically eiiicient.

It is usual in the design or a resonance chamher to provide an opening only at a point opposite to the chime bar, and the generally accepted theory has been that this was essential, but applicant has discovered that equally good results can he had by leaving one end of the resonance chamber open and properly dimensioning the size of the opening in the side wall as well as the shape of the chamber. These factors serve to tune the chamber properly, with the result that the resonant frequency of vibration of the air column inside the chamber is the same as the frequency of vibration of the sound bar.

With this arrangement, the parts can be compactly arranged in a small compass with the chime bars located within the resonance chamhers, and the entire structure enclosed by the housing fitting closely thereover, but without detracting irom the tone quality oi the mechanism. llllith the arrangement of openings in the end walls of the housing oppositely to the open ends of the resonance chambers, it has been found that tones of suficlent volume can be obtained for all practical purposes in telephone signaling operations. The housing can be attached to a bridge or horizontal support ti on the base by means of suitable bolts til extending through openings in the housing and entering thread openings it in the bridge 2?, or it may be otherwise secured thereto.

While the invention has been described with reference to the embodiment herein disclosed, it is not confined to the details and arrangement shown, but the application is intended to cover any modifications or departures coming within the purposes of the improvement, or the scope of the following claims.

We claim:

1. In a signal device, the combination with a. resonance chamber and a chime bar located parallel to one of its side walls, the resonance chamher being closed at one end and open at its opposite end and having an opening in the side wall adjacent to said chime bar, of a solenoid, and a. plunger movable at right angles to the longitudinal axis of the resonance chamber and carrying a striker for engagement with said chime bar.

2- In' a signal device, the combination with a resonance chamber and a chime bar located parallel to one oi its side walls within the reschance chamber, said resonance chamber having one end closed and its opposite end open, and said side wall having an opening opposite to said chime bar, of a solenoid, and a plunger movable at right angles to the longitudinal axis of the resonance chamber and carrying a striker movable through said opening in the side wall for engagement with said chime bar.

3. In a signal device, the combination with upper and vlower resonance chambers, each of said resonance chambers having-a closed end and an open end, of a chime bar for each resonance chamber located parallel to one of its side walls, said side wall having an opening opposlte to the chime bar, a solenoid looatw between-the resonance chambers having a plunger movable at right angles to the longitudinal axes of said chambers, strikers carried by the ends of the plunger for engagement with said chime bars, and a housing including end walls with openings therein arranged oppositely to the open ends of the resonance chambers.

4. In a signal device, the combination with upper and lower resonance chambers, each of said resonance chambers having a closed end and an open end, of a chime bar in each resonance chamber located parallel to one of its side walls, said side wall having an opening opposite to the chime bar, a solenoid located between the resonance chambers having a plunger movable at right angles to the longitudinal axes of the chambers, strikers carried by the ends of the plunger and movable through said openings in the side walls for engagement with said chime bars, and a housing including end walls with openings therein arranged oppositely to the open ends of the resonance chambers.

5. In a signal device, the combination with a resonance chamber and a chime bar located parallel to one of its side walls, the resonance chamber being closed at one end and open at its opposite end and having an opening in the side wall adjacent to said chime bar, of a solenoid, a plunger movable at right angles to the longitudinal axis of the resonance chamber and carrying a striker for engagement with said chime bar, and a housing enclosing the resonance chamber and including a wall having openings opposite to said open end of the resonance chamber.

6; In a signal device, the combination with a resonance chamber and a chime bar located parallel to one of its side walls within the resonance 1 chamber, said resonance chamber having one end closed and its opposite end open, and said side wall having an opening opposite to said chime bar, of a solenoid, a plunger movable at right angles to the longitudinal axis of the resonance chamber and carrying a striker movable through said opening in the side wall for engagement with said chime bar, and a housing enclosing the resonance chamber and including a wall having openings therein opposite to said open end of the resonance chamber.

'7. In a signal device, the combination with upper and lower resonance chambers, each of said resonance chambers having a closed end and.

an open end, of a chime bar for each resonance chamber located parallel to one of its side walls. said side wall having an opening opposite to the chime bar, a solenoid located between the resonance chambers having a plunger movable at right angles to the longitudinal axes of said chambers, strikers carried by the ends of the plunger for engagement with said chime bars. and a housing including end walls with openings therein arranged oppositely to the open ends oi! the resonance chambers, the open end of one resonance chamber being located at the end of the housing opposite to the open end of the other resonance chamber.

' KENNETH M. LORD. GLENN E. WARREN. 

